Catalytic processes using heterogeneous, bulk, oxide-supported catalysts are notoriously well known. They form the backbone of much of today's chemical industry. However, although these catalyst systems are exceptionally flexible in that they often produce high catalytic turnover rates and their use result in processes in which the catalyst is easily separable from the feed and products, the actual chemical composition of the active sites often remains a mystery. The mechanistic activities at those catalytic sites are similarly difficult to determine. Attempts to circumvent these shortcomings have primarily focused on chemically binding discreet, well-characterized, metallic or organometallic complexes to a support, typically polymer or silicious substrate, thereby making previously soluble organometallic complexes insoluble and atomically dispersed. However, the usefulness of these "heterogenized" complexes as catalysts is limited by the same analytical difficulties associated with characterizing in doing mechanistic studies on bulk solid, two-phase systems.
This invention represents the first example of organic solvent-soluble, atomically dispersed, oxide-supported catalyst precursors, using covalently-bonded iridium-heteropolyanions to oxidize cycloolefins to produce oxygenates.
Certain of these oxygenation catalyst precursors have been disclosed in U.S. patent Ser. No. 020,122, filed Feb. 27, 1987 now abandoned, and its continuation-in-part, Ser. No. 07/275,105, filed Oct. 26, 1988 now U.S. Pat. No. 5,116,796. The earlier applications did not suggest the use of these materials as oxidation catalysts.